Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in JAVA):

Solution:
import java.util.*;

import javax.lang.model.util.ElementScanner6;

import java.io.*;

public class Main {
	static class FastReader {
		BufferedReader br;
		StringTokenizer st;

		public FastReader() {
			br = new BufferedReader(new InputStreamReader(System.in));
		}

		String next() {
			while (st == null || !st.hasMoreElements()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return st.nextToken();
		}

		int nextInt() {
			return Integer.parseInt(next());
		}

		long nextLong() {
			return Long.parseLong(next());
		}

		double nextDouble() {
			return Double.parseDouble(next());
		}

		String nextLine() {
			String str = "";
			try {
				str = br.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
			return str;
		}
	}
  static HashSet<Integer>H=new HashSet<>(); static int count=0;
 


	public static void main(String[] args) throws FileNotFoundException {
		
	 FastReader scan=new FastReader();
	
  /*int t=scan.nextInt();
  while(t-->0){
	  long n=scan.nextLong();
	  long k=scan.nextLong();
	  long a[]=new long[(int)n];
	  for(long i=0;i<n;++i){
		  a[(int)i]=scan.nextInt();
	  }
	  ArrayList<Long>left=new ArrayList<>();
	  ArrayList<Long>Right=new ArrayList<>();
	  for(int i=0;i<a.length;++i){
		   long sum=k-a[i];
		   if(!left.contains(sum)){
			   left.add(a[i]);
		   }
		   else
		   if(!Right.contains(sum)){
			   Right.add(a[i]);
		   }
		   else{
			   //Count the number having less number of than sum
				long check1=check(left,sum);
				long check2=check(Right,sum);
				if(check1>check2){
                   Right.add(a[i]);
				}
				else{
					left.add(a[i]);
				}
		   }
	  }
	 
	  for(int i=0;i<a.length;++i){
		  if(Right.contains(a[i])){
			  System.out.print(0+" ");
			  Right.remove(Right.lastIndexOf(a[i]));
			  
		  }
		else
		if(left.contains(a[i])){
			System.out.print(1+" ");
			left.remove(left.lastIndexOf(a[i]));
		
		}
		  
	  }
	  System.out.println();


  }
 System.out.println();
	*/
	String m=scan.nextLine();
	m=m.replaceAll(", ", "");
	

	HashSet<Character>H=new HashSet<>();
	for(int i=1;i<m.length()-1;++i){
	
      H.add(m.charAt(i));
	}
	System.out.println(H.size());
	}
	static long check(ArrayList<Long>A,long sum){
		Iterator it=A.iterator();
		long count=0;
		while(it.hasNext()){
				  long temp=(long)it.next();
				  if(temp==sum){
					  ++count;
				  }
		}
		return count;
	}
	















		  }